title: Repair of oronasal fistulae by interposition of multilayered amniotic membrane allograft.
abstract: BACKGROUND
  Oronasal fistulas are a frequent complication after cleft palate surgery. Numerous repair methods have been described, but wound-healing problems occur often. The authors investigated, for the first time, the suitability of multilayered amniotic membrane allograft for fistula repair in a laboratory experiment (part A), a swine model (part B), and an initial patient series (part C).
  
  
  METHODS
  In part A, one-, two-, and four-layer porcine and human amniotic membranes (n = 20 each) were fixed in a digital towing device and the force needed for rupture was determined. In part B, iatrogenic oronasal fistulas in 18 piglets were repaired with amniotic membrane allograft, autofetal amniotic membrane, or small intestinal submucosa (n = 6 each). Healing was evaluated by probing and visual inflammation control (no/moderate/strong) on postoperative days 3, 7, 10, and 76. Histological analysis was performed to visualize tissue architecture. In part C, four patients (two women and two men, ages 21 to 51 years) were treated with multilayered amniotic membrane allograft.
  
  
  RESULTS
  In part A, forces needed for amniotic membrane rupture increased with additional layers (p < 0.001). Human amniotic membrane was stronger than porcine membrane (p < 0.001). In part B, fistula closure succeeded in all animals treated with amniotic membrane with less inflammation than in the small intestinal submucosa group. One fistula remained persistent in the small intestinal submucosa group. In part C, all fistulas healed completely without inflammation.
  
  
  CONCLUSIONS
  Amniotic membrane is an easily available biomaterial and can be used successfully for oronasal fistula repair. The multilayer technique and protective plates should be utilized to prevent membrane ruptures.
  
  
  METHODS
  Therapeutic, V.
authors.affiliation: Munich, Oberschleissheim, and Bochum, Germany; Linz, Austria; and Southampton, Hampshire, United Kingdom From the Department of Oral and Maxillofacial Surgery, Technische Universität München; Department of Oral and Maxillofacial Surgery, General Hospital of Linz; Clinic for Swine, Faculty of Veterinary Medicine, Ludwig-Maximilians-University of Munich; Department of Oral and Maxillofacial Surgery, Southampton University Hospital NHS Foundation Trust; and Department of Plastic Surgery, Burn Unit, BG University Hospital Bergmannsheil, Ruhr University Bochum.
authors.forename: Nils H
authors.initials: NH
authors.lastname: Rohleder
authors.forename: Denys J
authors.initials: DJ
authors.lastname: Loeffelbein
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Feistl
authors.forename: Matthias
authors.initials: M
authors.lastname: Eddicks
authors.forename: Klaus-D
authors.initials: KD
authors.lastname: Wolff
authors.forename: Aakshay
authors.initials: A
authors.lastname: Gulati
authors.forename: Lars
authors.initials: L
authors.lastname: Steinstraesser
authors.forename: Marco R
authors.initials: MR
authors.lastname: Kesting
mesh_terms: D000818:Animals; D001684:Biological Dressings; D002972:Cleft Palate / Q000601:surgery; D005260:Female; D005402:Fistula / Q000601:surgery; D006801:Humans; D008297:Male; D009666:Nose / Q000601:surgery*; D009668:Nose Diseases / Q000209:etiology / Q000601:surgery*; D016155:Oral Fistula / Q000209:etiology / Q000601:surgery*; D019647:Oral Surgical Procedures / Q000379:methods*; D011183:Postoperative Complications; D019651:Plastic Surgery Procedures / Q000009:adverse effects; D013552:Swine; D014184:Transplantation, Homologous; D016896:Treatment Outcome; D014945:Wound Healing